468
/
838
Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
R/X: Both R and X are detection bits, the difference is that R means that the card detects an anomaly in the
command interpretation and verification phase (response mode), while X means that the card detects an anomaly
in the command execution phase (execution mode).
SDIO card host can read these bits by sending a status command to query the status of the card.
Clear condition:
A: According to the current state of the card
B: Always relative to the previous command. Cleared when the correct command is received, this method has a
delay of one command.
C: Read clear
SD status register
The SD status contains not only status bits related to specific functions of the SD memory card, but also some status
bits related to future applications. The length of the SD state is a 512-bit data block. After receiving the ACMD13
command (CMD55, then CMD13), the content of the SD status register is transferred to the SDIO card host. But it
should be noted that ACMD13 commands can only be sent when the card is in the transmitting state (the card has
been selected).
Table 18-8 defines the different SD status register information.
Table 18-8 SD Status
Bits
Identifier
Type
Value
Description
Clear
condition
511:510
DAT_BUS_WIDTH
SR
‘00’= 1 (Default)
‘01’= Reserved
‘10’= 4 Bit width
‘11’= Reserved
The current data
bus width as
defined by the
SET_BUS_WIDTH
command.
A
509
SECURED_MODE
SR
‘0’= Not in privacy mode
‘1’= In privacy mode
The card is in
secure operation
mode (see "SD
Security
Specification" for
details).
A
508:496
Reserved
495:480
SD_CARD_TYPE
SR
‘00xxh’= SD memory card in
physical specification version
1.01~2.00 ('x' means any
value). The defined cards are:
'0000'= Regular SD RD/WR
Card
'0001'= SD ROM Card
The lower 8 bits of
this field can define
different variants of
SD memory cards
in the future (each
bit can be used to
define a different
SD type). The
A